Locks an individual page in the form and displays a status message.

<div class="definition">
    lockPage(page, [message])
</div>

<div class="arguments">
    <table>
        <tr>
            <td>page</td>
            <td><b>number</b>, zero indexed page number</td>
        </tr>
    <tr>
        <td>message</td>
        <td><b>string</b>, <i>optional</i>,  message to display</td>
    </tr>
    </table>
</div>

Returns <i>boolean</i>.

<h4>Description</h4>

This method will lock a page in the form by adding a semi-transparent div on top of its content. The user will not be able to interact with
the page's content until the page is unlocked with <a href="w2form.unlockPage" class="method">.unlockPage()</a> or <a href="w2form.unlock" class="method">.unlock()</a>.
This method will call <a href="w2utils.lock" class="method">w2utils.lock()</a> to perform the locking.
<div style="height: 10px"></div>

If you have following form:
<textarea class="javascript">
let form = new w2form({
    name     : 'form',
    formURL  : '/server/path',
    fields: [
        { field: 'first_name', type: 'text', required: true, html: { page: 1 } },
        { field: 'last_name', type: 'text', required: true, html: { page: 1 } },
        { field: 'email', type: 'email', html: { page: 1 } }
    ],
    actions: {
        "save": function (target, data) { this.validate(); },
        "reset": function (target, data) { this.clear(); }
    }
});
</textarea>

Lock with a message:
<textarea class="javascript">
w2ui.form.lockPage(1, 'Cannot access now');
</textarea>